From 320128c7ebb162b7990012170561eba23a0c960d Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Fri, 30 Oct 2009 02:55:54 -0500
Subject: [PATCH] move histogram to math.statistics, write a main article for
 math.statistics

---
 basis/math/statistics/statistics-docs.factor  | 104 +++++++++++++++++-
 basis/math/statistics/statistics-tests.factor |  10 ++
 basis/math/statistics/statistics.factor       |  33 +++++-
 extra/histogram/histogram-docs.factor         |  87 ---------------
 extra/histogram/histogram-tests.factor        |  12 --
 extra/histogram/histogram.factor              |  29 -----
 6 files changed, 141 insertions(+), 134 deletions(-)
 delete mode 100755 extra/histogram/histogram-docs.factor
 delete mode 100755 extra/histogram/histogram-tests.factor
 delete mode 100755 extra/histogram/histogram.factor

diff --git a/basis/math/statistics/statistics-docs.factor b/basis/math/statistics/statistics-docs.factor
index 1a29d611f9..dc54f4181f 100644
--- a/basis/math/statistics/statistics-docs.factor
+++ b/basis/math/statistics/statistics-docs.factor
@@ -1,4 +1,5 @@
-USING: help.markup help.syntax debugger ;
+USING: assocs debugger hashtables help.markup help.syntax
+quotations sequences ;
 IN: math.statistics
 
 HELP: geometric-mean
@@ -58,3 +59,104 @@ HELP: var
   { $example "USING: math.statistics prettyprint ;" "{ 1 2 3 } var ." "1" }
   { $example "USING: math.statistics prettyprint ;" "{ 1 2 3 4 } var ." "1+2/3" } } ;
 
+
+HELP: histogram
+{ $values
+    { "seq" sequence }
+    { "hashtable" hashtable }
+}
+{ $examples 
+    { $example "! Count the number of times an element appears in a sequence."
+               "USING: prettyprint histogram ;"
+               "\"aaabc\" histogram ."
+               "H{ { 97 3 } { 98 1 } { 99 1 } }"
+    }
+}
+{ $description "Returns a hashtable where the keys are the elements of the sequence and the values are the number of times they appeared in that sequence." } ;
+
+HELP: histogram*
+{ $values
+    { "hashtable" hashtable } { "seq" sequence }
+    { "hashtable" hashtable }
+}
+{ $examples 
+    { $example "! Count the number of times the elements of two sequences appear."
+               "USING: prettyprint histogram ;"
+               "\"aaabc\" histogram \"aaaaaabc\" histogram* ."
+               "H{ { 97 9 } { 98 2 } { 99 2 } }"
+    }
+}
+{ $description "Takes an existing hashtable and uses " { $link histogram } " to continue counting the number of occurences of each element." } ;
+
+HELP: sequence>assoc
+{ $values
+    { "seq" sequence } { "quot" quotation } { "exemplar" "an exemplar assoc" }
+    { "assoc" assoc }
+}
+{ $examples 
+    { $example "! Iterate over a sequence and increment the count at each element"
+               "USING: assocs prettyprint histogram ;"
+               "\"aaabc\" [ inc-at ] H{ } sequence>assoc ."
+               "H{ { 97 3 } { 98 1 } { 99 1 } }"
+    }
+}
+{ $description "Iterates over a sequence, allowing elements of the sequence to be added to a newly created " { $snippet "assoc" } " according to the passed quotation." } ;
+
+HELP: sequence>assoc*
+{ $values
+    { "assoc" assoc } { "seq" sequence } { "quot" quotation }
+    { "assoc" assoc }
+}
+{ $examples 
+    { $example "! Iterate over a sequence and add the counts to an existing assoc"
+               "USING: assocs prettyprint histogram kernel ;"
+               "H{ { 97 2 } { 98 1 } } clone \"aaabc\" [ inc-at ] sequence>assoc* ."
+               "H{ { 97 5 } { 98 2 } { 99 1 } }"
+    }
+}
+{ $description "Iterates over a sequence, allowing elements of the sequence to be added to an existing " { $snippet "assoc" } " according to the passed quotation." } ;
+
+HELP: sequence>hashtable
+{ $values
+    { "seq" sequence } { "quot" quotation }
+    { "hashtable" hashtable }
+}
+{ $examples 
+    { $example "! Count the number of times an element occurs in a sequence"
+               "USING: assocs prettyprint histogram ;"
+               "\"aaabc\" [ inc-at ] sequence>hashtable ."
+               "H{ { 97 3 } { 98 1 } { 99 1 } }"
+    }
+}
+{ $description "Iterates over a sequence, allowing elements of the sequence to be added to a hashtable according to the passed quotation." } ;
+
+ARTICLE: "histogram" "Computing histograms"
+"Counting elements in a sequence:"
+{ $subsections
+    histogram
+    histogram*
+}
+"Combinators for implementing histogram:"
+{ $subsections
+    sequence>assoc
+    sequence>assoc*
+    sequence>hashtable
+} ;
+
+ARTICLE: "math.statistics" "Statistics"
+"Computing the mean:"
+{ $subsections mean geometric-mean harmonic-mean }
+"Computing the median:"
+{ $subsections median lower-median upper-median medians }
+"Computing the mode:"
+{ $subsections mode }
+"Computing the standard deviation and variance:"
+{ $subsections std var }
+"Computing the range and minimum and maximum elements:"
+{ $subsections range minmax }
+"Computing the kth smallest element:"
+{ $subsections kth-smallest }
+"Counting the frequency of occurrence of elements:"
+{ $subsection "histogram" } ;
+
+ABOUT: "math.statistics"
diff --git a/basis/math/statistics/statistics-tests.factor b/basis/math/statistics/statistics-tests.factor
index 32ebcbc6a1..0d3172f685 100644
--- a/basis/math/statistics/statistics-tests.factor
+++ b/basis/math/statistics/statistics-tests.factor
@@ -43,3 +43,13 @@ IN: math.statistics.tests
 [ 0 ] [ { 1 } var ] unit-test
 [ 0.0 ] [ { 1 } std ] unit-test
 [ 0.0 ] [ { 1 } ste ] unit-test
+
+[
+    H{
+        { 97 2 }
+        { 98 2 }
+        { 99 2 }
+    }
+] [
+    "aabbcc" histogram
+] unit-test
diff --git a/basis/math/statistics/statistics.factor b/basis/math/statistics/statistics.factor
index dad0970855..9c72b848ca 100644
--- a/basis/math/statistics/statistics.factor
+++ b/basis/math/statistics/statistics.factor
@@ -45,7 +45,8 @@ IN: math.statistics
     k seq nth ; inline
 
 : lower-median ( seq -- elt )
-    dup dup length odd? [ midpoint@ ] [ midpoint@ 1 - ] if kth-smallest ;
+    [ ] [ ] [ length odd? ] tri
+    [ midpoint@ ] [ midpoint@ 1 - ] if kth-smallest ;
 
 : upper-median ( seq -- elt )
     dup midpoint@ kth-smallest ;
@@ -54,13 +55,35 @@ IN: math.statistics
     [ lower-median ] [ upper-median ] bi ;
 
 : median ( seq -- x )
-    dup length odd? [ lower-median ] [ medians + 2 / ] if ;
+    [ ] [ length odd? ] bi [ lower-median ] [ medians + 2 / ] if ;
 
-: frequency ( seq -- hashtable )
-    H{ } clone [ '[ _ inc-at ] each ] keep ;
+<PRIVATE
+
+: (sequence>assoc) ( seq quot assoc -- assoc )
+    [ swap curry each ] keep ; inline
+
+PRIVATE>
+
+: sequence>assoc* ( assoc seq quot: ( obj assoc -- ) -- assoc )
+    rot (sequence>assoc) ; inline
+
+: sequence>assoc ( seq quot: ( obj assoc -- ) exemplar -- assoc )
+    clone (sequence>assoc) ; inline
+
+: sequence>hashtable ( seq quot: ( obj hashtable -- ) -- hashtable )
+    H{ } sequence>assoc ; inline
+
+: histogram* ( hashtable seq -- hashtable )
+    [ inc-at ] sequence>assoc* ;
+
+: histogram ( seq -- hashtable )
+    [ inc-at ] sequence>hashtable ;
+
+: collect-values ( seq quot: ( obj hashtable -- ) -- hash )
+    '[ [ dup @ ] dip push-at ] sequence>hashtable ; inline
 
 : mode ( seq -- x )
-    frequency >alist
+    histogram >alist
     [ ] [ [ [ second ] bi@ > ] 2keep ? ] map-reduce first ;
 
 : minmax ( seq -- min max )
diff --git a/extra/histogram/histogram-docs.factor b/extra/histogram/histogram-docs.factor
deleted file mode 100755
index fc463cabfe..0000000000
--- a/extra/histogram/histogram-docs.factor
+++ /dev/null
@@ -1,87 +0,0 @@
-IN: histogram
-USING: help.markup help.syntax sequences hashtables quotations assocs ;
-
-HELP: histogram
-{ $values
-    { "seq" sequence }
-    { "hashtable" hashtable }
-}
-{ $examples 
-    { $example "! Count the number of times an element appears in a sequence."
-               "USING: prettyprint histogram ;"
-               "\"aaabc\" histogram ."
-               "H{ { 97 3 } { 98 1 } { 99 1 } }"
-    }
-}
-{ $description "Returns a hashtable where the keys are the elements of the sequence and the values are the number of times they appeared in that sequence." } ;
-
-HELP: histogram*
-{ $values
-    { "hashtable" hashtable } { "seq" sequence }
-    { "hashtable" hashtable }
-}
-{ $examples 
-    { $example "! Count the number of times the elements of two sequences appear."
-               "USING: prettyprint histogram ;"
-               "\"aaabc\" histogram \"aaaaaabc\" histogram* ."
-               "H{ { 97 9 } { 98 2 } { 99 2 } }"
-    }
-}
-{ $description "Takes an existing hashtable and uses " { $link histogram } " to continue counting the number of occurences of each element." } ;
-
-HELP: sequence>assoc
-{ $values
-    { "seq" sequence } { "quot" quotation } { "exemplar" "an exemplar assoc" }
-    { "assoc" assoc }
-}
-{ $examples 
-    { $example "! Iterate over a sequence and increment the count at each element"
-               "USING: assocs prettyprint histogram ;"
-               "\"aaabc\" [ inc-at ] H{ } sequence>assoc ."
-               "H{ { 97 3 } { 98 1 } { 99 1 } }"
-    }
-}
-{ $description "Iterates over a sequence, allowing elements of the sequence to be added to a newly created " { $snippet "assoc" } " according to the passed quotation." } ;
-
-HELP: sequence>assoc*
-{ $values
-    { "assoc" assoc } { "seq" sequence } { "quot" quotation }
-    { "assoc" assoc }
-}
-{ $examples 
-    { $example "! Iterate over a sequence and add the counts to an existing assoc"
-               "USING: assocs prettyprint histogram kernel ;"
-               "H{ { 97 2 } { 98 1 } } clone \"aaabc\" [ inc-at ] sequence>assoc* ."
-               "H{ { 97 5 } { 98 2 } { 99 1 } }"
-    }
-}
-{ $description "Iterates over a sequence, allowing elements of the sequence to be added to an existing " { $snippet "assoc" } " according to the passed quotation." } ;
-
-HELP: sequence>hashtable
-{ $values
-    { "seq" sequence } { "quot" quotation }
-    { "hashtable" hashtable }
-}
-{ $examples 
-    { $example "! Count the number of times an element occurs in a sequence"
-               "USING: assocs prettyprint histogram ;"
-               "\"aaabc\" [ inc-at ] sequence>hashtable ."
-               "H{ { 97 3 } { 98 1 } { 99 1 } }"
-    }
-}
-{ $description "Iterates over a sequence, allowing elements of the sequence to be added to a hashtable according to the passed quotation." } ;
-
-ARTICLE: "histogram" "Computing histograms"
-"Counting elements in a sequence:"
-{ $subsections
-    histogram
-    histogram*
-}
-"Combinators for implementing histogram:"
-{ $subsections
-    sequence>assoc
-    sequence>assoc*
-    sequence>hashtable
-} ;
-
-ABOUT: "histogram"
diff --git a/extra/histogram/histogram-tests.factor b/extra/histogram/histogram-tests.factor
deleted file mode 100755
index f0e7b3e80e..0000000000
--- a/extra/histogram/histogram-tests.factor
+++ /dev/null
@@ -1,12 +0,0 @@
-IN: histogram.tests
-USING: help.markup help.syntax tools.test histogram ;
-
-[
-    H{
-        { 97 2 }
-        { 98 2 }
-        { 99 2 }
-    }
-] [
-    "aabbcc" histogram
-] unit-test
diff --git a/extra/histogram/histogram.factor b/extra/histogram/histogram.factor
deleted file mode 100755
index d5c6ab3778..0000000000
--- a/extra/histogram/histogram.factor
+++ /dev/null
@@ -1,29 +0,0 @@
-! Copyright (C) 2009 Doug Coleman.
-! See http://factorcode.org/license.txt for BSD license.
-USING: kernel sequences assocs fry ;
-IN: histogram
-
-<PRIVATE
-
-: (sequence>assoc) ( seq quot assoc -- assoc )
-    [ swap curry each ] keep ; inline
-
-PRIVATE>
-
-: sequence>assoc* ( assoc seq quot: ( obj assoc -- ) -- assoc )
-    rot (sequence>assoc) ; inline
-
-: sequence>assoc ( seq quot: ( obj assoc -- ) exemplar -- assoc )
-    clone (sequence>assoc) ; inline
-
-: sequence>hashtable ( seq quot: ( obj hashtable -- ) -- hashtable )
-    H{ } sequence>assoc ; inline
-
-: histogram* ( hashtable seq -- hashtable )
-    [ inc-at ] sequence>assoc* ;
-
-: histogram ( seq -- hashtable )
-    [ inc-at ] sequence>hashtable ;
-
-: collect-values ( seq quot: ( obj hashtable -- ) -- hash )
-    '[ [ dup @ ] dip push-at ] sequence>hashtable ; inline